Cambridge A Level Information Technology (from 2017) 9626 — 2024 May/June Paper 3 · Variant 3

1 JavaScript uses loops to execute a block of code using Iterative methods. (a) Describe what is meant by an Iterative method. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) Explain how a do/while loop differs from a while loop. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (c) Explain why a while loop might be used instead of a for loop in JavaScript code. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1]

Mark scheme: 1(a) Two from:  Repeatedly/repeats/over and over (1st) One from: works through the elements (of an array/block) (1) Operates/performs an operation on every element of an array/block (1) Works on the elements (of an array/block) one at a time (1). 2 1(b) Two from:  In a do…while loop the condition to be checked is placed at the end of the code block//in a (plain) while loop it is at the start of the code block  In a do…while loop the condition is tested after the code block is run//in a while loop it is tested before the code block is run  The do…while loop will always execute the block of code at least once//a while loop may not execute the code block at all. 2 1(c) One from:  A while loop is used when the number of iterations is not known/undetermined // a for loop is used when the number of iterations is known beforehand/already determined  A while loop continues as long as a condition is true/until a condition is met // the number of iterations in a for loop is pre-determined by the iteration statement/uses a counter. 1

2 Describe how stroke and fill settings can be used to change the appearance of text in a computer animation. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 2 Six from: Max 5 from: Stroke is:  an outline around the text letters  Can be animated to move around the letters  Can be set to fade in/out around the letters  Can be set to different formats/colours e.g. dotted/dashed/thickness  Can be set to different corner formats e.g. sharp/smooth/rounded Max 5 from: Fill:  changes the contents of the letter shapes  Change the colour of the letter/shape (content/interior)  Use of (multicolour) colour gradients to gradually change one colour into another  linear gradients change colour along a single axis (horizontal or vertical)  radial gradients change colour in an outward/inward direction starting from/to a central focal point  direction/focal point of gradient can be changed.

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3 Developers can use either evolutionary or throw-away prototyping to create prototypes of a new interface. (a) Describe two advantages of using evolutionary prototyping. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) Describe one disadvantage of using evolutionary prototyping. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (c) Describe two advantages of using throw-away prototyping. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (d) Describe one disadvantage of using throw-away prototyping. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1]

Mark scheme: 3(a) Two from:  The delivery of the system is speeded up  The user engages with the system  The system is more likely to meet the user requirements. 2 3(b) One from:  Not knowing when to stop the development/extended development time/takes a long time  Opinions/views/comments come from a biased/small group. 1 3(c) Two from:  The advantage of this approach is the speed with which the prototype is put together  To ensure that the (system) requirements are clearly understood/validated  It focuses the user on only one aspect of the system/keeps the feedback precise. 2 3(d) One from:  All the man-hours/effort/research/work/resources used to create the throw away prototypes are lost/total cost of project increased.  Developers may be pressurised by the users to deliver the prototype/it as a final product. 1

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4 Discuss the benefits of the use of vision enhancement in health care. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 4 Command word: Discuss: write about issue(s) or topic(s) in depth in a structured way. One from: Vision enhancement is designed to provide visually impaired persons with images of their surroundings in order to enable them to work/navigate/enjoy their surroundings Eight from, e.g.:  Use of HD camera and smart glasses for vision impaired persons that project images into eyes so that focus/detail are enhanced which means that wearer is independent of others/has increased mobility  Use of smart glasses with augmented reality to overlay details/highlight environmental features/change the colours of signs so that wearer is more informed of dangers/hazards/independent/safe/mobile  Use of devices to improve vision/direct images to centre of retina in sufferers of macular degeneration so that images from peripheral vision/images can be seen/improved  Use in macular degeneration sufferers can improve facial recognition of other people  which improves communication/interactions  Use of remote assistive technology/smart devices linked to certified agents/visual interpreter/support personnel that respond when visually impaired wearer taps/asks with help/assistance  so wearer can avoid hazards/navigate surroundings  Use of retinal implants connected to camera/glasses to directly stimulate nerves with signals to allow brain to interpret environment  so wearer has some direct sense of surroundings  Use of night vision goggles/glasses to enhance vision in low-light/darkness … to enable visually impaired persons to navigate surroundings/use technology/so they can work/drive at night  Use by surgeons/doctors when carrying out surgery so that less invasive techniques/more precise surgery can be carried improves patient recovery rates/speed of recovery. Max 6 marks if bullets/list of points. 8

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5 Computer devices can connect to a local area network (LAN). Wi-Fi connections can only be used within range of a wireless access point (WAP). (a) Explain why Wi-Fi connections to a WAP have a limited range. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (b) Explain how the connection range of Wi-Fi can be increased. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] Devices use ethernet technology to send data on cabled LANs. (c) Explain why ethernet technology is used on LANs to send data. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4]

Mark scheme: 5(a) Three from:  Wi-Fi transmitters/WAP are restricted to (very) low power  The radio waves/signals degrade/do not travel/propagate over long distances/are attenuated over distance  Do not penetrate solid objects/walls very well/easily/some materials can block Wi-Fi signals  Ensures that Wi-Fi can be used in networks that are close together/in homes/apartments/business sharing buildings  Ensure they do not interfere with each other  Ensure that they are less accessible to eavesdroppers  Because of interference from other transmissions (e.g.: from other devices)  Reduces the/any possibility of (any) (perceived) harmful effects on human health. 3 5(b) Three from:  Place WAPs in open environment/high up/unimpeded by objects/walls so that radio waves are not obstructed/signal strength is reduced  Install additional/WAPs/extenders/repeaters/booster/use powerline connections (so that blind-spots are covered)  Increase power output of WAP (1st) so that radio waves travel further (1)  Use 2.4GHz (frequencies) (instead of 5Ghz frequencies) (1st) this has greater range/radio waves at this frequency travel further/can penetrate objects better (1)  Ensure that WAP uses channels that are not used by adjacent/overlapping/neighbours channels  avoid (co-channel) interference which can slow/impede data transmission. 3 5(c) Four from:  Transmission media/cables are robust/resistant to electrical noise/interference/resistant to data degradation  Can achieve very high rates of data transfer/high bandwidths compared to other methods of connection/data transfer.  More secure than wireless/high security  Ethernet uses a connectionless mode of communication/no acknowledgment of frames (1st) so less network traffic (1)  All nodes/devices (on Ethernet) have the same privileges/no client-server issues/negotiation needed  No routing required/possible/no need for hubs or switches. 4

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6 Describe how a system flowchart is constructed. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [5]

Mark scheme: 6 Five from:  A graphical/diagram/drawing representation of a system  Inputs/outputs in/of a system  Processes in/of a system  Lines/arrows used to show route(s) through the system  Symbols to represent/show the inputs/outputs and processes in/of a system  Sequence of events/processes that occur in a system  Steps/tasks/events within a process in a system  Relationships/links between the elements/stages in a system and external elements  Different routes control events  Start/end/stop of the flowchart Shown by terminators 5

7 A specialist data mining company has been asked by a bank to create a data mining model. The bank will use the model to find out if there is fraudulent activity in the use of credit cards. Describe the process the data mining company will use to create the model for the bank. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 7 Eight from: Max 1 mark for naming at least 3 stages: business understanding, data understanding, data preparation, data modelling, evaluating, deployment. Business understanding:  which determines what is required from the data mining process  Deciding if the data mining is worth the cost/risk of being carried out  Deciding the success criteria of the data mining process Data understanding:  which collects/identifies the data sets to be used  Ensuring that there is enough data available to carry out the mining process  Ensuring that there is enough time/computer resources available to carry out the data mining  Creating a description/report on the data sets to be used Data preparation:  selects the data to be used according to e.g. its relevance to the company’s requirements  ‘Cleaning’ the data to remove redundant/inaccurate/irrelevant data  Creating combinations of data by merging data with common characteristics/features/customer uses Data modelling:  out the mining to discover relationships/links/patterns in the data  Creating new relationships/links/patterns to analyse the patterns  Document the mining to allow repetition/testing/evaluation of the results Evaluating:  the process against the success criteria  If the success criteria are not met the model is amended and rerun  If the success criteria are met the company is shown the results to assess Deployment:  of the data mining model for use by company/the data mining model is passed to the bank for use/run for the bank  Full documentation is created so the process can be repeated/monitored/maintained. 8

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8 Web browsers are clients which request services, such as web pages, from a web server. This is an example of the use of the client-server model of networking. Justify the use of client-server networking in this scenario. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 8 Command word: Justify: support a case with evidence/argument. Six from:  New clients/web browsers can be added/join/connect to the server as and when required without the need for changes in configurations  New/more servers can be added as and when demand/traffic increases without users/browsers being disrupted  Control is centralised because all requests are to the server/no client can control the system so security is enhanced/increased  Server resources/new technology can be updated without reference/need to change/update clients/browsers websites can be centrally updated/managed  Centralised control of backup means that clients/web browsers/users do not need to take action/can be automated  Servers can be accessed/used by/from many different platforms/applications/users. 6

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9 Project management software (PMS) is used to support a project. (a) Explain how PMS can be used for the scheduling of tasks in a project. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4] (b) Explain why using PMS may not be appropriate for very small projects. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4]

Mark scheme: 9(a) Four from:  Shows/stores/holds the milestones/tasks/activities/deliverables  Has tools to put milestones/tasks/activities into sequence/order shows dependencies between tasks  Estimation of the duration of activities/tasks to enable calculation of costs to enable allocation of resources  Tracking of team members during tasks/activities enables monitoring/reporting of work progress collaboration between team members  Automatic updating when tasks/activities are changed/completed enable automatic reporting to managers  Visual representation. 4 9(b) Four from:  PMS is expensive to purchase/install/use  cost may be more than the project cost/uneconomical  PMS can be complex to use/set up/needs training  PMS may take too long to set up/use  May take too much training/learning for a small project  May not be worth the effort to set up for a small project. 4

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10 Discuss the benefits and drawbacks to individuals of using chat rooms for social networking. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 10 Command word: Discuss: write about issue(s) or topic(s) in depth in a structured way. Eight from: Max 6 from: Benefits e.g.:  Can use chat rooms anonymously so identity is protected  Can meet new people with different views to expand knowledge/experiences  Can get/research/find out about perspectives from around the world which expands/enhances ideas/opinions  Can (easily) discover people based on user’s characteristics/age/gender identity/interests/goals to communicate with people of similar background  Can be free/cheap to use after internet access is paid for so little additional cost/outlay required to communicate over long distances  Can carry out other tasks while ‘chatting’ so increases work rate compared to e.g. telephone conversations  Can offer unbiased/unfiltered opinions as users do not know each other/act as ‘safety valves’ for strong emotions/opinions that would not be expressed in real life  Can be restricted to specific topics to provide in-depth discussions  Can pretend to be someone else to avoid bias/discrimination Max 6 from: Drawbacks e.g.  Cannot be certain that other users are being honest/that they are who they say they are/catfishing  (Often) text-based so emotions/facial expressions are not possible resulting in confusions/ misunderstandings between users  Other online users exploit vulnerable users/coerce/persuade them into illegal/inappropriate activities/behaviour/meetings  Chat rooms can result in ‘flame wars’ where two or more users enter exchange insults/abuse sparked by a minor disagreement  Trolling/cyber-bullying can be more frequent  Building relationships online can result in less time spent with friends and family. Max 6 marks if bullets/list of points. 8

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